I am engaged and the wedding date is in only three months. I share a ton of mutual interests with my fiancée. We are both committed and growing Christians. We pray together. We are doing some pre-marital discussions with a mentoring couple. I have spent enough time with her to know that she is far from perfect and so am I.
The problem is, I just can't get a constant feeling of peace. I find myself constantly evaluating her and wondering if she is really putting her heart into this relationship. I am afraid she just wants to get married. I feel so lost because I love her deeply, and I don't want to let go, but I don't want to be stuck if God has a better plan. What do I do?
For starters, I don't know how much of this you've shared with your fiancée, your mentoring couple, your pastor or your parents, but you need to tell somebody who is close to the situation what your concerns are. If you're seriously questioning whether to call off the engagement, you need to share your thoughts with the appropriate people.
At least one of the purposes of your engagement season is to do exactly what you're doing — make sure you've made the right decision. That means that even though it is obviously your intention to marry, it's entirely appropriate to postpone, or even call off, a wedding if necessary. Yes, it can be upsetting and disruptive and all of those things, but not nearly so as divorce.
But do your concerns rise to that level? Let's see.
You wonder if she is really "putting her heart" into the relationship. That could mean dozens of things, some small and some not so small. If by "not putting her heart into it" you mean she's apathetic about you and the marriage, and that seems fairly obvious to not only you but also others, then that is indeed a problem. If, on the other hand, it means she's just not text messaging you as often as you are her, then that's quite another issue.
For example, that she might be indifferent, say, about certain details of the wedding ceremony or who gives a speech at the reception, is likely not apathy about you or the relationship. It probably means she just really doesn't have a strong opinion about it either way. What is of much greater interest to me is whether she is indifferent about the level of emotional intimacy between the two of you. If there is a growing emotional distance, rather than closeness, and that's what you mean by "not putting her heart into it," then yes, that is a problem.
Now, how can you gauge "emotional intimacy"? Well, it's more than having some common interests. It's great that you and your fiancée have so much in common, that you're both pursuing Christ and that you pray together. But I could say the same thing about me and the guys in my men's Bible study. What should make the two of you different from me and the guys is that you have a vision for growing old together, spending a lifetime becoming one, and leaving a legacy of sacrificial love to your children and grandchildren.
When we were engaged, one of the ways I knew my wife was really in it for the long haul was that we spent a lot of time talking and dreaming about the future. Not just the next couple of years, but the next 50 years, and not just about careers and castles, but how we hoped to model to those around us a marriage that shone the light and love of Christ, especially as it played out in our love for one another.
We loved watching her grandparents walking hand-in-hand because it gave us a vision for the legacy we hoped to leave for our children and grandchildren. We knew that what we were getting ourselves into was much, much bigger than our own happiness. It was about bringing glory to the One who brought us together, and cheering each other on to run and finish the race as best we could. My wife wanted that, and she wanted it with me. I know, because we talked about it.
And that's what you need to find out. A) Does your fiancée want that kind of marriage legacy? and, B) Does she want it with you? If her answer is an energetic "yes!" and "yes!" then you're in good shape; everything else is details. Yes, those details are important, and you'll spend your entire marriage working on them, but without first having the proper foundation, the details really don't matter much.
Here's a little article I wrote about my wife's grandparents and the legacy they left for us. Maybe you can think of a creative way to use it to help spark some dreaming between you and your fiancée. If she's energized by that dreaming, then I'm guessing "her heart is in it." If she flatlines, that's a red flag you need to explore — quickly.